Imaging lens system and camera module

ABSTRACT

A camera module includes a first lens having positive refractive power; a second lens having refractive power; a third lens having positive refractive power, and having a concave shape on an image side surface; a fourth lens having negative refractive power; and a fifth lens having refractive power. TTL, a distance from an object side surface of the first lens to an imaging surface and BFL, a distance from an image side surface of the fifth lens to the imaging surface satisfy 1.0&lt;TTL/BFL&lt;3.0.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 USC 119(a) of Korean PatentApplication No. 10-2019-0127269, filed on Oct. 14, 2019 with the KoreanIntellectual Property Office, the entire disclosure of which isincorporated herein by reference for all purposes.

BACKGROUND 1. Field

The following description relates to a camera module capable of varyingan optical axis length and a lens imaging system mountable in such acamera module.

2. Description of Background

A portable terminal commonly includes a camera module. For example, aportable wireless terminal may include one or more camera modules. Eachcamera module may have a predetermined size. For example, a cameramodule may have a size corresponding to a distance from a lens closestto an object to an image side surface (or an image sensor), known as atotal track length (TTL). The TTL of the camera module is usuallyproportional to a focal length. For example, a camera module fornear-distance imaging may have a shorter TTL than a conventional cameramodule. As another example, a camera module for long-distance imagingmay have a longer TTL than a conventional camera module. However, sincethe portable wireless terminal has a limited installation space, it maybe difficult to mount a camera module for long-distance imaging or acamera module capable of magnification control of an image (azoom-enabled camera module).

SUMMARY

This Summary is provided to introduce a selection of concepts insimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

A lens imaging system capable of long-distance imaging while beingmounted on a portable terminal, and a camera module including the same.

In one general aspect, a camera module includes: a first lens havingpositive refractive power; a second lens having refractive power, athird lens having positive refractive power, and having a concave shapeon an image side surface; a fourth lens having negative refractivepower; and a fifth lens having refractive power. TTL, a distance from anobject side surface of the first lens to an imaging surface, and BFL, adistance from an image side surface of the fifth lens to the imagingsurface, satisfies 1.0<TTL/BFL<3.0.

The first lens may have a convex image-side surface.

The third lens may have a convex object-side surface.

The fifth lens may have a concave image-side surface.

A radius of curvature of an image side surface of the first lens L1 R2and a focal length f of the lens imaging system may satisfy−10<L1R2/f<−2.0.

A radius of curvature of the object-side surface of the first lens L1 R1and a radius of curvature of an image-side surface of the first lens L1R2 may satisfy −2.0<(L1R1+L1R2)/(L1R1−L1R2)<−0.1.

A radius of curvature of an image side surface of the second lens L2R2and a focal length f of the lens imaging system may satisfy0.1<L2R2/f<2.0.

A radius of curvature of an object side surface of the second lens L2R1and a radius of curvature of an image side surface of the second lensL2R2 may satisfy 0.1<(L2R1+L2R2)/(L2R1−L2R2)<5.0.

The BFL and a diagonal length 2 lmgHT of the imaging surface may satisfy1.0<BFL/2 lmgHT.

A total field of view (FOV) may be 35 degrees or less.

A focal length f of the lens imaging system and a diagonal length 2lmgHT of the imaging surface may satisfy 1.6<f/2 lmgHT.

The fifth lens may have positive refractive power.

In another general aspect, a camera module includes a first barrelincluding a lens imaging system; and a second barrel coupled to thefirst barrel, and including an image sensor. The first barrel isaccommodated inside the second barrel in an optical axis direction ofthe lens imaging system.

The lens imaging system may include a first lens having positiverefractive power; a second lens having refractive power; a third lenshaving positive refractive power, and including a concave image-sidesurface; a fourth lens having negative refractive power; and a fifthlens having refractive power. TTL, a distance from an object-sidesurface of the first lens to an imaging surface, and BFL, a distancefrom an image-side surface of the fifth lens to the imaging surface, maysatisfy 1.0<TTL/BFL<3.0.

A length of the first barrel in the optical axis direction may begreater than a distance from the object side surface of the first lensto the image side surface of the fifth lens.

In another general aspect, a camera module includes a first lens barrel;a second lens barrel coupled to an image side of the first barrel; alens imaging system accommodated within the first lens barrel and thesecond lens barrel; and a third lens barrel including an image sensor,and accommodating the first lens barrel and the second lens barreltherein. The lens imaging system includes a first lens having refractivepower; a second lens having refractive power; a third lens havingrefractive power; a fourth lens having refractive power; and a fifthlens having refractive power. TTL, a distance from an object-sidesurface of the first lens to an imaging surface, and BFL, a distancefrom an image-side surface of the fifth lens to the imaging surface,satisfies 1.0<TTL/BFL<3.0.

The first lens, the second lens, and the third lens may be accommodatedin the first lens barrel, and the fourth lens and the fifth lens may beaccommodated in the second lens barrel.

A length of the first lens barrel in an optical axis direction may begreater than a distance from the object-side surface of the first lensto an image-side surface of the third lens.

A length of the second lens barrel in an optical axis direction may begreater than a distance from an object-side surface of the fourth lensto the image-side surface of the fifth lens.

A length of the third lens barrel in an optical axis direction may begreater than BFL.

Other features and aspects will be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a configuration diagram of a lens imaging system according toan example.

FIG. 2 is a configuration diagram of a camera module including the lensimaging system illustrated in FIG. 1.

FIG. 3 is a storage state diagram of the camera module illustrated inFIG. 2.

FIG. 4 is a configuration diagram of a lens imaging system according toanother example.

FIG. 5 is a configuration diagram of a camera module including the lensimaging system illustrated in FIG. 4.

FIGS. 6A and 6B are storage state diagrams of the camera moduleillustrated in FIG. 5.

FIG. 7 is a configuration diagram of a lens imaging system according toanother example.

FIG. 8 is a configuration diagram of a camera module including the lensimaging system illustrated in FIG. 7.

FIGS. 9A and 9B are storage state diagrams of the camera moduleillustrated in FIG. 8.

Throughout the drawings and the detailed description, the same referencenumerals refer to the same elements. The drawings may not be to scale,and the relative size, proportions, and depiction of elements in thedrawings may be exaggerated for clarity, illustration, and convenience.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the methods, apparatuses,and/or systems described herein. However, various changes,modifications, and equivalents of the methods, apparatuses, and/orsystems described herein will be apparent to one of ordinary skill inthe art. The sequences of operations described herein are merelyexamples, and are not limited to those set forth herein, but may bechanged as will be apparent to one of ordinary skill in the art, withthe exception of operations necessarily occurring in a certain order.Also, descriptions of functions and constructions that would be wellknown to one of ordinary skill in the art may be omitted for increasedclarity and conciseness.

The features described herein may be embodied in different forms, andare not to be construed as being limited to the examples describedherein. Rather, the examples described herein have been provided so thatthis disclosure will be thorough and complete, and will fully convey thescope of the disclosure to one of ordinary skill in the art.

Herein, it is noted that use of the term “may” with respect to anexample or embodiment, e.g., as to what an example or embodiment mayinclude or implement, means that at least one example or embodimentexists in which such a feature is included or implemented while allexamples and embodiments are not limited thereto.

Throughout the specification, when an element, such as a layer, region,or substrate, is described as being “on,” “connected to,” or “coupledto” another element, it may be directly “on,” “connected to,” or“coupled to” the other element, or there may be one or more otherelements intervening therebetween. In contrast, when an element isdescribed as being “directly on,” “directly connected to,” or “directlycoupled to” another element, there can be no other elements interveningtherebetween.

As used herein, the term “and/or” includes any one and any combinationof any two or more of the associated listed items.

Although terms such as “first,” “second,” and “third” may be used hereinto describe various members, components, regions, layers, or sections,these members, components, regions, layers, or sections are not to belimited by these terms. Rather, these terms are only used to distinguishone member, component, region, layer, or section from another member,component, region, layer, or section. Thus, a first member, component,region, layer, or section referred to in examples described herein mayalso be referred to as a second member, component, region, layer, orsection without departing from the teachings of the examples.

Spatially relative terms such as “above,” “upper,” “below,” and “lower”may be used herein for ease of description to describe one element'srelationship to another element as shown in the figures. Such spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. For example, if the device in the figures is turned over,an element described as being “above” or “upper” relative to anotherelement will then be “below” or “lower” relative to the other element.Thus, the term “above” encompasses both the above and below orientationsdepending on the spatial orientation of the device. The device may alsobe oriented in other ways (for example, rotated 90 degrees or at otherorientations), and the spatially relative terms used herein are to beinterpreted accordingly.

The terminology used herein is for describing various examples only, andis not to be used to limit the disclosure. The articles “a,” “an,” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. The terms “comprises,” “includes,”and “has” specify the presence of stated features, numbers, operations,members, elements, and/or combinations thereof, but do not preclude thepresence or addition of one or more other features, numbers, operations,members, elements, and/or combinations thereof.

Due to manufacturing techniques and/or tolerances, variations of theshapes shown in the drawings may occur. Thus, the examples describedherein are not limited to the specific shapes shown in the drawings, butinclude changes in shape that occur during manufacturing.

The features of the examples described herein may be combined in variousways as will be apparent after an understanding of the disclosure ofthis application. Further, although the examples described herein have avariety of configurations, other configurations are possible as will beapparent after an understanding of the disclosure of this application.

Hereinafter, examples will be described as follows with reference to theattached drawings.

Herein, a first lens refers to a lens closest to an object (or asubject), and a fifth lens refers to a lens closest to an imagingsurface (or an image sensor). Herein, a unit of a curvature of radius, athickness, TTL, 2 lmgHT (a diagonal length of the imaging surface), anda focal length of the lens may be in millimeters (mm). In addition, thethickness of the lens, an interval between the lenses, and the TTL is adistance from an optical axis of the lens. In addition, in anexplanation of a shape of each lens, a convex shape on one surface maymean an optical axis portion of the surface is convex, and a concaveshape of one surface may mean an optical axis portion of the surface isconcave. Therefore, even when one surface of the lens is described ashaving a convex shape, an edge portion of the lens may be concave.Similarly, even when one surface of the lens is described as having aconcave shape, an edge portion of the lens may be convex.

The lens imaging system includes an optical system comprised of aplurality of lenses. For example, the optical system of the lens imagingsystem is comprised of a plurality of lenses having refractive power.However, the lens imaging system is not comprised of only lenses havingrefractive power. For example, the lens imaging system may include astop ST for adjusting an amount of light. In addition, the lens imagingsystem may include an infrared cut filter for blocking infrared rays. Inaddition, the lens imaging system may further include an image sensor(i.e., an imaging device) for converting an image of a subject incidentthrough the optical system into an electrical signal. In addition, thelens imaging system may further include a gap maintenance member foradjusting the distance between the lens and the lens.

A plurality of lenses is made of materials having different refractiveindexes from air. For example, the plurality of lenses is made ofplastic or glass materials. At least one of the plurality of lenses hasan aspherical shape. The aspherical surface of the lens is representedby Equation 1 below.

$\begin{matrix}{Z = {\frac{{cr}^{2}}{{1 + \sqrt{1 - {\left( {1 + k} \right)c^{2}r^{2}}}}\;} + {Ar}^{4} + {Br}^{6} + {Cr}^{8} + {Dr}^{10} + {Er}^{12} + {Fr}^{14} + {Gr}^{16} + {Hr}^{18} + {Jr}^{20}}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

In Equation 1, c is a reciprocal of a radius of curvature of the lens, kis a conical constant, r is a distance from any point on an asphericalsurface to an optical axis, A through J are aspherical surfaceconstants, and Z (or SAG) is a height in an optical axis direction fromany point on an aspheric surface to an apex of the aspheric surface.

The lens imaging system includes five or more lenses. For example, thelens imaging system includes a first lens, a second lens, a third lens,a fourth lens, and a fifth lens, sequentially disposed from an objectside.

The first lens to the fifth lens may be disposed at intervals fromneighboring lenses. For example, an image side surface of the first lensmay not contact an object side surface of the second lens, and an imageside surface of the second lens may not contact an object side surfaceof the third lens.

The first lens has predetermined refractive power. For example, thefirst lens may have positive refractive power. The first lens has aconvex shape on one surface. For example, the first lens may have aconvex shape on an image side surface. The first lens has apredetermined refractive index. For example, the first lens may have arefractive index of 1.6 or more. The first lens has a predeterminedfocal length. For example, the focal length of the first lens may be ina range of 7.0 to 9.0 mm.

The second lens has predetermined refractive power. For example, thesecond lens may have negative refractive power. The second lens has aconcave shape on one surface. For example, the second lens may have aconcave shape on an image side surface. The second lens has apredetermined refractive index. For example, the second lens may have arefractive index of 1.0 or more and less than 1.6. The second lens has apredetermined focal length. For example, the focal length of the secondlens may be in a range of −10 to −7.0 mm.

The third lens has predetermined refractive power. For example, thethird lens has a concave shape on one surface. For example, the thirdlens may have a concave shape on an image side surface. The third lenshas a predetermined refractive index. For example, the third lens mayhave a refractive index of 1.6 or more and less than 1.8. The third lenshas a predetermined focal length. The focal length of the third lens maybe in a range of 30 to 100 mm.

The fourth lens has predetermined refractive power. For example, thefourth lens may have negative refractive power. The fourth lens has aconvex shape on one surface. For example, the fourth lens may have aconvex shape on an image side surface. The fourth lens has apredetermined refractive index. For example, the fourth lens may have arefractive index of 1.6 or more and less than 1.8. The fourth lens has apredetermined focal length. For example, the focal length of the fourthlens may be in a range of −30 to −15 mm.

The fifth lens has predetermined refractive power. For example, thefifth lens may have positive or negative refractive power. The fifthlens may have a concave shape on one surface. For example, the fifthlens may have a concave shape on an image side surface. The fifth lenshas predetermined refractive power. For example, the fifth lens may haverefractive power of 1.5 or more and less than 1.8. The fifth lens has apredetermined focal length. For example, the focal length of the fifthlens may be in a range of 12 to 24 mm.

The lens imaging system includes a lens of a plastic material. Forexample, in the lens imaging system, at least one of five or more lensesconstituting a lens group may be made of a plastic material.

The lens imaging system includes an aspherical lens. For example, in thelens imaging system, at least one of five or more lenses constitutingthe lens group may be an aspherical lens.

The lens imaging system may include a filter, a stop, and an imagesensor.

The filter is disposed between a lens disposed closest to the imagingsurface and the image sensor. The filter blocks some wavelengths oflight from incident light to improve a resolution of the lens imagingsystem. For example, the filter may block infrared light wavelengths ofthe incident light. The stop maybe disposed between the third lens andthe fourth lens.

The lens imaging system may satisfy one or more of the followingconditional expressions:

1.0<TTL/BFL<3.0;

−10.0<L1R2/f<−2.0;

−2.0<(L1R1+L1R2)/(L1R1−L1R2)<−0.1;

0.1<L2R2/f<2.0;

0.1<(L2R1+L2R2)/(L2R1−L2R2)<5.0;

0.1<f/f1<5.0;

0.1<f/f3<2.0;

−2.0<f/f4<−0.1; and

0.1<f/f5<2.0,

where TTL is a distance from an object side surface of the first lens toan imaging surface, BFL is a distance from an image side surface of thefifth lens to an imaging surface, f is a focal length of the lensimaging system, L1R1 is a radius of curvature of the object side surfaceof the first lens, L1 R2 is a radius of curvature of the image sidesurface of the first lens, L2R1 is a radius of curvature of the objectside surface of the second lens, L2R2 is a radius of curvature of theimage side surface of the second surface, f1 is a focal length of thefirst lens, f3 is a focal length of the third lens, f4 is a focal lengthof the fourth lens, and f5 is a focal length of the fifth lens.

In addition, the lens imaging system may further satisfy one or more thefollowing conditional expressions:

1.0<BFL/2 lmgHT;

1.6<f/2 lmgHT;

1.0<TTL/f<1.2;

0.8<(TTL−BFL)/BFL<1.1;

D23/D34<1;

T5<T4<T1;

max(|1/f2|,|1/f3|,|1/f4|,|1/f5|)<|1/f1|; and

FOV<35,

where 2 lmgHT is a diagonal length of the imaging surface, D23 is adistance from the image side surface of the second lens to the objectside surface of the third lens, D34 is a distance from the image sidesurface of the third lens to the object side surface of the fourth lens,T1 is a thickness at a center of an optical axis of the first lens, T4is a thickness at a center of an optical axis of the fourth lens, T5 isa thickness at a center of an optical axis of the fifth lens, max( )indicates the largest value listed in parentheses, and FOV is a totalfield of view of the lens imaging system.

Next, a lens imaging system according to various examples will bedescribed.

A lens imaging system according to a first example will be describedwith reference to FIG. 1.

A lens imaging system 100 includes a first lens 110, a second lens 120,a third lens 130, a fourth lens 140, and a fifth lens 150.

The first lens 110 has positive refractive power. The first lens 110 hasa convex shape on an object side surface and a convex shape on an imageside surface. The second lens 120 has negative refractive power. Thesecond lens 120 has a convex shape on an object side surface and aconcave shape on an image side surface. The third lens 130 has positiverefractive power. The third lens 130 has a convex shape on an objectside surface and a concave shape on an image side surface. The fourthlens 140 has negative refractive power. The fourth lens 140 has aconcave shape on an object side surface and a convex shape on an imageside surface. The fifth lens 150 has positive refractive power. Thefifth lens 150 has a convex shape on an object side surface and aconcave shape on an image side surface.

The first lens 110 may be the thickest lens in the lens imaging system100. For example, the thickness at the center of the first lens 110along the optical axis may be greater than the thickness at the centerof the second lens 120 to the fifth lens 150 along the optical axis.

The lens imaging system 100 may include a filter 170 and an image sensor180. The filter 170 is disposed between the fifth lens 150 and the imagesensor 180. The filter 170 is configured to block light of a specificwavelength from incident light. The image sensor 180 is disposed on animage side of the filter 170. The image sensor 180 is configured toconvert an optical signal into an electrical signal.

Table 1 shows lens characteristics of the lens imaging system 100, andTable 2 shows aspherical values of the lens imaging system 100.

TABLE 1 Radius Re- Surface Refer- of Thickness/ Focal fractive Abbe No.ence curvature distance length index number 0 Object infinity infinity 1First 4.450 1.61828 7.93099 1.5350 56.00 lens 2 −85.103 0.06000 3 Second9.340 1.12000 −8.85139 1.6150 25.90 lens 4 3.300 1.00000 5 Third 17.9500.58349 35.85586 1.6600 20.40 lens 6 70.482 1.60000 7 Fourth −3.3001.40000 −19.29506 1.6150 25.90 lens 8 −5.190 0.04000 9 Fifth 3.6511.20000 17.36149 1.5350 56.00 lens 10 5.199 7.20242 11 Filter infinity0.11000 1.5441 56.00 12 infinity 0.87054 13 Imaging infinity 0.00020surface

TABLE 2 Sur- face No. K A B C D E F G H I 1 −0.61556653 0.0008381862.08291E−05  4.32584E−06 −4.64091E−07  3.62323E−08 0 0.00E+00 0.00E+000.00E+00 2  0.00E+00  6.22E−05  −5.78E−06  3.53684E−06 −4.65702E−07  2.8652E−08 0.00E+00 0.00E+00 0.00E+00 0.00E+00 3  0.00E+00 −4.04E−037.95822E−05  9.36203E−07 −2.07702E−07 0 0.00E+00 0.00E+00 0.00E+000.00E+00 4  0.00E+00 −5.30E−03 0.00016213 −1.30902E−05 −4.56916E−06 00.00E+00 0.00E+00 0.00E+00 0.00E+00 5  0.00E+00  1.57E−03 0.001414701−0.000284243 2.44754E−05 0 0.00E+00 0.00E+00 0.00E+00 0.00E+00 6 0.00E+00  3.74E−04 −0.001382994 −0.000620431 8.74698E−05 −6.52082E−060.00E+00 0.00E+00 0.00E+00 0.00E+00 7  0.00E+00  2.19E−02 −0.0052599130.000825143 −5.50761E−05 −3.51393E−06 0.00E+00 0.00E+00 0.00E+000.00E+00 8 −5.40E+00  1.97E−03 −0.000675279 0.00025125 −7.31796E−06−1.39381E−06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 9  0.00E+00 −1.41E−020.001855935 −6.50915E−05 −4.06056E−06  2.54792E−07 0.00E+00 0.00E+000.00E+00 0.00E+00 10  0.00E+00 −7.08E−03 0.000840088 −4.19774E−058.41651E−06 −3.04125E−07 0.00E+00 0.00E+00 0.00E+00 0.00E+00

A camera module including the lens imaging system 100 will be describedwith reference to FIGS. 2 and 3.

A camera module 10 includes the lens imaging system 100 and lens barrels20 and 30. However, the configuration of the camera module 10 is notlimited to the lens imaging system 100 and the lens barrels 20 and 30.For example, the camera module 10 may further include a drivingmechanism for driving the lens imaging system 100 or the lens barrels 20and 30.

The lens barrels 20 and 30 may be configured in plural. For example, thelens barrels 20 and 30 may be comprised of the first lens barrel 20 andthe second lens barrel 30. The first lens barrel 20 is configured toaccommodate a partial configuration of the lens imaging system 100. Forexample, the first lens barrel 20 may be configured to accommodate thelenses 110, 120, 130, 140, and 150 of the lens imaging system 100. Thefirst lens barrel 20 has a predetermined length BL1. For example, thelength BL1 of the first lens barrel 20 may be greater than a distanceD16 from the object side surface of the first lens 110 to the image sidesurface of the fifth lens 150. The second lens barrel 30 is configuredto accommodate a remaining configuration of the lens imaging system 100.For example, the second lens barrel 30 may be configured to accommodatethe filter 170 and the image sensor 180 of the lens imaging system 100.The second lens barrel 30 has a predetermined length BL2. For example,the length BL2 of the second lens barrel 30 may be greater than thedistance BFL from the image side surface of the fifth lens to theimaging surface of the image sensor 180.

The first lens barrel 20 may be accommodated inside the second lensbarrel 30. For example, the first lens barrel 20 may be completelyaccommodated in the second lens barrel 30 as shown in FIG. 3 so that anoverall height of the camera module 10 may be reduced. A protrusion 22and a guide groove 32 are formed in the first lens barrel 20 and thesecond lens barrel 30, respectively. For example, one or moreprotrusions 22 are formed on an outer circumferential surface of thefirst lens barrel 20, and the same number of guide grooves 32 are formedon an inner circumferential surface of the second lens barrel 30. Theguide groove 32 is formed to be elongated in a longitudinal direction ofthe second lens barrel 30. The protrusion 22 of the first lens barrel 20is fitted into the guide groove 32 of the second lens barrel 30.

The first lens barrel 20 and the second lens barrel 30 may be coupled toeach other by the protrusion 22 and the guide groove 32. The first lensbarrel 20 may move in the optical axis direction along the innercircumferential surface of the second lens barrel 30. For example, thefirst lens barrel 20 may freely move in the optical axis directionthrough the protrusion 22 coupled with the guide groove 32.

The camera module 10 configured as described above may be easily mountedto the portable terminal since the height of the camera module 10 isadjusted by the plurality of lens barrels 20 and 30.

A lens imaging system according to a second example will be describedwith reference to FIG. 4.

A lens imaging system 200 includes a first lens 210, a second lens 220,a third lens 230, a fourth lens 240, and a fifth lens 250.

The first lens 210 has positive refractive power. The first lens 210 hasa convex shape on an object side surface and a convex shape on an imageside surface. The second lens 220 has negative refractive power. Thesecond lens 220 has a convex shape on an object side surface and aconcave shape on an image side surface. The third lens 230 has positiverefractive power. The third lens 230 has a convex shape on an objectside surface and a concave shape on an image side surface. The fourthlens 240 has negative refractive power. The fourth lens 240 has aconcave shape on an object side surface and a convex shape on an imageside surface. The fifth lens 250 has positive refractive power. Thefifth lens 250 has a convex shape on an object side surface and aconcave shape on an image side surface.

The first lens 210 may be the thickest lens in the lens imaging system200. For example, the thickness at the center of the first lens 210along the optical axis may be greater than the thickness at the centerof the second lens 220 to the fifth lens 250 along the optical axis.

The lens imaging system 200 may include a filter 270 and an image sensor280. The filter 270 is disposed between the fifth lens 250 and the imagesensor 280. The filter 270 is configured to block light of a specificwavelength from incident light. For example, the filter may beconfigured to block light of infrared wavelengths. The image sensor 280is disposed on the image side of the filter 270. The image sensor 280 isconfigured to convert an optical signal into an electrical signal.

Table 3 shows lens characteristics of the lens imaging system 200, andTable 4 shows aspherical values of the lens imaging system 200.

TABLE 3 Radius Re- Surface Refer- of Thickness/ Focal fractive Abbe No.ence curvature distance length index number 0 Object infinity infinity 1First 4.459 1.84752 7.98272 1.5350 56.00 lens 2 −92.924 0.06000 3 Second9.434 1.11825 −8.79211 1.6150 25.90 lens 4 3.300 1.00000 5 Third 25.0680.55279 46.09704 1.6600 20.40 lens 6 133.042 1.60000 7 Fourth −3.3001.40000 21.86904 1.6150 25.90 lens 8 −4.944 0.04000 9 Fifth 3.6901.15477 17.19018 1.5350 56.00 lens 10 5.336 7.20242 11 Filter infinity0.11000 1.5441 56.00 12 infinity 0.76999 13 Imaging infinity 0.00154surface

TABLE 4 Surface No. K A B C D E F G H I 1 −0.61719 0.000834 2.29E−053.42E−06 −3.26E−07 2.57E−08 0.00E+00 0.00E+00 0 0 2 0 6.36E−05 −5.48E−063.86E−06 −5.93E−07 3.83E−08 0.00E+00 0.00E+00 0 0 3 0 −0.00402 0.000139−8.18E−06 2.67E−07 0.00E+00 0.00E+00 0.00E+00 0 0 4 0 −0.00538 0.000447−3.21E−05 −3.62E−06 0.00E+00 0.00E+00 0.00E+00 0 0 5 0 0.000891 0.002096−0.0004 3.31E−05 0.00E+00 0.00E+00 0.00E+00 0 0 6 0 0.000369 0.001905−0.00071 9.12E−05 −6.74E−06 0.00E+00 0.00E+00 0 0 7 0 0.021828 −0.005680.001048 −9.85E−05 −9.86E−07 0.00E+00 0.00E+00 0 0 8 −4.42031 0.001103−0.0006 0.000276 −1.84E−05 −4.72E−07 0.00E+00 0.00E+00 0 0 9 0 −0.014720.002374 −0.00016 3.23E−06 5.72E−08 0.00E+00 0.00E+00 0 0 10 0 −0.006668.35E−04 −2.38E−05 5.08E−06 −1.68E−07 0.00E+00 0.00E+00 0 0

Next, a camera module including the lens imaging system 200 will bedescribed with reference to FIGS. 5, 6A, and 6B.

The camera module 12 includes a lens imaging system 200 described aboveand lens barrels 20, 30, and 40. However, the configuration of thecamera module 12 is not limited to the lens imaging system 200 and thelens barrels 20, 30, and 40. For example, the camera module 12 mayfurther include a driving mechanism for driving the lens imaging system200 or the lens barrels 20, 30, and 40.

The lens barrels 20, 30, and 40 may be configured in plural. Forexample, the lens barrels 20, 30, and 40 may be comprised of the firstlens barrel 20, the second lens barrel 30, and the third lens barrel 40.The first lens barrel 20 may be configured to accommodate a partialconfiguration of the lens imaging system 200. For example, the firstlens barrel 20 may be configured to accommodate lenses 210, 220, and 230of the lens imaging system 200. The first lens barrel 20 has apredetermined length BL1. For example, the length BL1 of the first lensbarrel 20 may be greater than a distance D13 from the object sidesurface of the first lens 210 to the image side surface of the thirdlens 230. The second lens barrel 30 is configured to accommodate theremaining lenses of the lens imaging system 200. For example, the secondlens barrel 30 may be configured to accommodate the fourth lens 240 andthe fifth lens 250. The second lens barrel 30 has a predetermined lengthBL2. For example, the length BL2 of the second lens barrel 30 may begreater than a distance D45 from the object side surface of the fourthlens 240 to the image side surface of the fifth lens 250. The third lensbarrel 40 may accommodate the remaining configurations of the lensimaging system 200. For example, the third lens barrel 40 may beconfigured to accommodate the filter 170 and the image sensor 180 of thelens imaging system 200. The third lens barrel 40 has a predeterminedlength BL3. For example, the length BL3 of the third lens barrel 40 maybe greater than a distance BFL from the image side surface of the fifthlens 250 to an imaging surface of the image sensor 280.

The first lens barrel 20 and the second lens barrel 30 are configured tobe accommodated in the third lens barrel 40. For example, the first lensbarrel 20 and the second lens barrel 30 may be completely accommodatedinside the third lens barrel 40 in an inactive state of the cameramodule 12.

Optionally, the second lens barrel 30 may be configured to be disposedoutwardly of the third lens barrel 40. For example, the second lensbarrel 30 may be disposed outwardly of the third lens barrel 40 throughan opening 42 of the third lens barrel 40. The opening 42 is formed onone side of the third lens barrel 40. The third lens barrel 40 mayinclude a cover 44 for selectively opening and closing the opening 42.The cover 44 may be coupled to the third lens barrel 40 by a hingemember 48.

A lens imaging system according to a third example will be describedwith reference to FIG. 7.

A lens imaging system 300 include a first lens 310, a second lens 320, athird lens 330, a fourth lens 340, and a fifth lens 350.

The first lens 310 has positive refractive power. The first lens 310 hasa convex shape on an object side surface and a convex shape on an imageside surface. The second lens 320 has negative refractive power. Thesecond lens 320 has a convex shape on an object side surface and aconcave shape on an image side surface. The third lens 330 has positiverefractive power. The third lens 330 has a convex shape on an objectside surface and a concave shape on an image side surface. The fourthlens 340 has negative refractive power. The fourth lens 340 has aconcave shape on an object side surface and a convex shape on an imageside surface. The fifth lens 350 has positive refractive power. Thefifth lens 350 has a convex shape on an object side surface and aconcave shape on an image side surface.

The first lens 310 may be the thickest lens in the lens imaging system300. For example, the thickness at a center of the first lens 310 alongthe optical axis may be greater than the thickness of the second lens320 to the fifth lens 350 at a center along the optical axis.

The lens imaging system 300 may include a filter 370 and an image sensor380. The filter 370 is disposed between the fifth lens 350 and the imagesensor 380. The filter 370 is configured to block light of a specificwavelength from incident light. For example, the filter 370 may beconfigured to block light of infrared wavelengths. The image sensor 380is disposed on an image side of the filter 370. The image sensor 380 isconfigured to convert an optical signal into an electrical signal.

Table 5 shows lens characteristics of the lens imaging system 300, andTable 6 shows aspherical values of the lens imaging system 300.

TABLE 5 Radius Re- Surface Refer- of Thickness/ Focal fractive Abbe No.ence curvature distance length index number 0 Object infinity infinity 1First 4.463 1.94240 8.04964 1.5350 56.00 lens 2 −113.792 0.04374 3Second 8.755 1.06248 −9.22173 1.6150 25.90 lens 4 3.300 1.00000 5 Third26.295 0.52045 88.81893 1.6600 20.40 lens 6 46.871 1.60000 7 Fourth−3.300 1.40000 −25.88373 1.6150 25.90 lens 8 −4.723 0.04000 9 Fifth3.703 1.18153 17.46759 1.5350 56.00 lens 10 5.312 7.26707 11 Filterinfinity 0.11000 1.5441 56.00 12 infinity 0.73945 13 Imaging infinity0.00055 surface

TABLE 6 Surface No. K A B C D E F G H I 1 −0.61371 0.000831 3.13E−052.88E−06 −3.61E−07 3.96E−08 0.00E+00 0.00E+00 0 0 2 0 8.96E−05 4.59E−063.74E−06 −7.67E−07 7.15E−08 0.00E+00 0 0 0 3 0 −0.00398 0.000133−1.00E−05 4.31E−07 0.00E+00 0.00E+00 0 0 0 4 0 −0.00522 0.000513−6.36E−05 1.26E−06 0.00E+00 0.00E+00 0 0 0 5 0 0.000659 0.00261−6.26E−04 6.66E−05 0.00E+00 0.00E+00 0 0 0 6 0 0.000396 0.002585−9.87E−04 1.25E−04 −5.35E−06 0.00E+00 0 0 0 7 0 0.02093 −0.005068.04E−04 −6.69E−05 −8.87E−07 0.00E+00 0 0 0 8 −3.83206 0.000683 −0.000480.000182 −4.13E−06 −9.41E−07 0.00E+00 0 0 0 9 0 −0.01398 0.00217−0.00015 3.68E−06 2.01E−08 0.00E+00 0 0 0 10 0 −0.00653 0.000817−1.81E−05 2.57E−06 8.59E−08 0.00E+00 0 0 0

Table 7 shows optical property values of the lens imaging systemaccording to the first to third examples.

TABLE 7 First Second Third Reference example example example TTL 16.80516.857 16.908 BFL 8.183 8.084 8.117 f 15.00 15.00 15.00 F-number 2.8002.800 2.800 2ImgHT 8.000 8.000 8.000

TABLE 8 First Second Third Conditional expression example exampleexample TTL/BFL 2.0536 2.0853 2.0830 L1R2/f −5.6735 −6.1949 −7.5861(L1R1 + L1R2)/(L1R1 − L1R2) −0.9006 −0.9084 −0.9245 L2R2/f 0.2200 0.22000.2200 (L2R1 + L2R2)/(L1R1 − L2R2) 2.0928 2.0760 2.2098 f/f1 1.89131.8791 1.8634 f/f3 0.4183 0.3254 0.1689 f/f4 −0.7774 −0.6859 −0.5795f/f5 0.8640 0.8726 0.8587 BFL/2ImgHT 1.0229 1.0105 1.0146 f/2ImgHT1.8750 1.8750 1.8750 TTL/f 1.1203 1.1238 1.1272 (TTL − BFL)/BFL 1.05361.0853 1.0830 D23/D34 0.6250 0.6250 0.6250 FOV 29.460 29.460 29.500

Next, a camera module including the lens imaging system 300 will bedescribed with reference to FIGS. 8, 9A, and 9B.

The camera module 14 includes the lens imaging system described above300 and lens barrels 20, 30, and 40. However, the configuration of thecamera module 14 is not limited to the lens imaging system 300 and thelens barrels 20, 30, and 40. For example, the camera module 10 mayfurther include a driving mechanism for driving the lens imaging system300 or the lens barrels 20, 30, and 40.

The lens barrels 20, 30, and 40 may be configured in plural. Forexample, the lens barrels 20, 30, and 40 may include the first lensbarrel 20, the second lens barrel 30, and the third lens barrel 40. Thefirst lens barrel 20 may be configured to accommodate a partialconfiguration of the lens imaging system 300. For example, the firstlens barrel 20 may be configured to accommodate lenses 310, 320, and 330of the lens imaging system 300. The first lens barrel 20 has apredetermined length BL1. For example, the length BL1 of the first lensbarrel 20 may be greater than a distance D13 from the object sidesurface of the first lens 310 to the image side surface of the thirdlens 330. The second lens barrel 30 is configured to accommodate theremaining lenses of the lens imaging system 300. For example, the secondlens barrel 30 may be configured to accommodate the fourth lens 340 andthe fifth lens 350. The second lens barrel 30 has a predetermined lengthBL2. For example, the length BL2 of the second lens barrel 30 may begreater than a distance D45 from the object side surface of the fourthlens 340 to the image side surface of the fifth lens 350. The third lensbarrel 40 may accommodate the remaining configurations of the lensimaging system 300. For example, the third lens barrel 40 may beconfigured to accommodate the filter 370 and the image senor 380 of thelens imaging system 300. The third lens barrel 40 has a predeterminedlength BL3. For example, the length BL3 of the third lens 40 may begreater than the distance BFL from the image side surface of the fifthlens 350 to the imaging surface of the image sensor 380.

The first lens barrel 20 and the second lens barrel 30 are configured tobe accommodated in the third lens barrel 40. For example, the first lensbarrel 20 and the second lens barrel 30 may be completely accommodatedinside the third lens barrel 40 in an inactive state of the cameramodule 14.

Optionally, the second lens barrel 30 may be configured to be disposedoutwardly of the third lens barrel 40. For example, the second lensbarrel 30 may be disposed outwardly of the third lens barrel 40 throughan opening 42 of the third lens barrel 40. The opening 42 is formed onone side of the third lens barrel 40. The third lens barrel 40 mayinclude a cover 44 for selectively opening and closing the opening 42.The cover 44 may be coupled to the third lens barrel 40 by a hingemember 48.

The second lens barrel 30 may be coupled to the first lens barrel 20 bya hinge member 28. Therefore, the second lens barrel 30 may be rotatearound the hinge member 28, and may be disposed in an up-and-downinverted state, as shown in FIG. 9B, while being carried out through theopening 42.

As set forth above, according to the examples, a lens imaging system anda camera module capable of high magnification imaging may be provided.

While this disclosure includes specific examples, it will be apparent toone of ordinary skill in the art that various changes in form anddetails may be made in these examples without departing from the spiritand scope of the claims and their equivalents. The examples describedherein are to be considered in a descriptive sense only, and not forpurposes of limitation. Descriptions of features or aspects in eachexample are to be considered as being applicable to similar features oraspects in other examples. Suitable results may be achieved if thedescribed techniques are performed to have a different order, and/or ifcomponents in a described system, architecture, device, or circuit arecombined in a different manner, and/or replaced or supplemented by othercomponents or their equivalents. Therefore, the scope of the disclosureis defined not by the detailed description, but by the claims and theirequivalents, and all variations within the scope of the claims and theirequivalents are to be construed as being included in the disclosure.

What is claimed is:
 1. A lens imaging system, disposed sequentially froman object side, comprising: a first lens having positive refractivepower, a second lens having refractive power; a third lens havingpositive refractive power, and comprising a concave image-side surface;a fourth lens having negative refractive power; and a fifth lens havingrefractive power, wherein TTL, a distance from an object-side surface ofthe first lens to an imaging surface, and BFL, a distance from animage-side surface of the fifth lens to the imaging surface, satisfy1.0<TTL/BFL<3.0.
 2. The lens imaging system of claim 1, wherein thefirst lens comprises a convex image-side surface.
 3. The lens imagingsystem of claim 1, wherein the third lens comprises a convex object-sidesurface.
 4. The lens imaging system of claim 1, wherein the fifth lenscomprises a concave image-side surface.
 5. The lens imaging system ofclaim 1, wherein a radius of curvature of an image side surface of thefirst lens L1R2 and a focal length f of the lens imaging system satisfy−10<L1R2/f<−2.0.
 6. The lens imaging system of claim 1, wherein a radiusof curvature of the object-side surface of the first lens L1R1 and aradius of curvature of an image-side surface of the first lens L1R2satisfy −2.0<(L1R1+L1R2)/(L1R1−L1R2)<−0.1.
 7. The lens imaging system ofclaim 1, wherein a radius of curvature of an image side surface of thesecond lens L2R2 and a focal length f of the lens imaging system satisfy0.1<L2R2/f<2.0.
 8. The lens imaging system of claim 1, wherein a radiusof curvature of an object side surface of the second lens L2R1 and aradius of curvature of an image side surface of the second lens L2R2satisfy 0.1<(L2R1+L2R2)/(L2R1−L2R2)<5.0.
 9. The lens imaging system ofclaim 1, wherein the BFL and a diagonal length 2 lmgHT of the imagingsurface satisfy 1.0<BFL/2 lmgHT.
 10. The lens imaging system of claim 1,wherein a total field of view (FOV) is 35 degrees or less.
 11. The lensimaging system of claim 1, wherein a focal length f of the lens imagingsystem and a diagonal length 2 lmgHT of the imaging surface satisfy1.6<f/2 lmgHT.
 12. The lens imaging system of claim 1, wherein the fifthlens has positive refractive power.
 13. A camera module, comprising: afirst barrel comprising a lens imaging system; and a second barrelcoupled to the first barrel, and comprising an image sensor, wherein thefirst barrel is configured to be accommodated inside the second barrelin an optical axis direction of the lens imaging system.
 14. The cameramodule of claim 13, wherein the lens imaging system comprises: a firstlens having positive refractive power; a second lens having refractivepower; a third lens having positive refractive power, and comprising aconcave image-side surface; a fourth lens having negative refractivepower; and a fifth lens having refractive power, wherein TTL, a distancefrom an object-side surface of the first lens to an imaging surface, andBFL, a distance from an image-side surface of the fifth lens to theimaging surface, satisfy 1.0<TTL/BFL<3.0.
 15. The camera module of claim14, wherein a length of the first barrel in the optical axis directionis greater than a distance from the object side surface of the firstlens to the image side surface of the fifth lens.
 16. A camera module,comprising: a first lens barrel; a second lens barrel coupled to animage side of the first barrel; a lens imaging system accommodatedwithin the first lens barrel and the second lens barrel, the lensimaging system comprising: a first lens having refractive power, asecond lens having refractive power; a third lens having refractivepower; a fourth lens having refractive power; and a fifth lens havingrefractive power; and a third lens barrel comprising an image sensor,and configured to accommodate the first lens barrel and the second lensbarrel therein, wherein 1.0<TTL/BFL<3.0, where TTL is a distance from anobject-side surface of the first lens to the image sensor and BFL is adistance from an image-side surface of the fifth lens to the imagesensor.
 17. The camera module of claim 16, wherein the first lens, thesecond lens, and the third lens are accommodated in the first lensbarrel, and the fourth lens and the fifth lens are accommodated in thesecond lens barrel.
 18. The camera module of claim 16, wherein a lengthof the first lens barrel in an optical axis direction is greater than adistance from the object-side surface of the first lens to an image-sidesurface of the third lens.
 19. The camera module of claim 16, wherein alength of the second lens barrel in an optical axis direction is greaterthan a distance from an object-side surface of the fourth lens to theimage-side surface of the fifth lens.
 20. The camera module of claim 16,wherein a length of the third lens barrel in an optical axis directionis greater than BFL.